Pneumatic bispatch-tube



(No Model.) 4 Sheets- 81mm; 1.

H. CLAY.

PNEUMAIIG DISPATCH TUBE. No. 307,437. Patented Nov. 4, 1884.

WITNESSES. ZNVENTOR A? y 47 W ATTORNEY 4 Sheets-Sheet 2.

(No Model.)

H. CLAY. PNEUMATIC DISPATCH TUBE. N0. 307,437. Patented NOV. 4, 1884.

Q q I o W r b M a O o N N x N Q \R 3 0 N VQN W o g b k 0 Q Q N 0 N 3* K; a NJWFMWM Q Q *6 0 2 Q5 LIEQTS m \M WITNESSES: [NVEZVTOR ATTORNEY N. PETERS. Phuioiithognpher. Washington D. C.

(No Model.) 4 Sheets-Sheet 3. H. CLAY.

' PNEUMATIGDISPATGH TUBE. No. 807,437. Patented Nov. 4, 1884.

WITNESSES: ZZVVENTOR ATTORNEY PETERS. Phnlcdjlhogmphor. wasningtun, DC.

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nurse ,ra'rns Farmer hrice,

PNEUMATIC DiSPATCH -TU B E.

SPECIFICATION forming part of Letters Patent No. 307,437, dated November 4, 1884:. Application tiled August 15, 1883. (No model.)

To all whom it may concern.-

Be it knownthat I, HENRY CLAY, a citizen of the United States, residing at Philadelphia, in the, county of Philadelphia and State of Pennsylvania, have invented certain new and useful Improvements in Pneumatic Dispatch- Tubes, of' which the following is a specification, reference being had therein to the accompanying drawings, wherein Figure 1 is a View, partly sectional, of a D01" tion of .ma'iudeliverytube with branches, manual switches, and sub-station boxes, together with eentral-offi ee electromagnetic devices for controlling the movements of said switches.

Fig. 2 is a section. partly in elevation, of branch delivery and receiving tubes, sub-station boxes, and automatic switch mechanism for said tubes. Fig. 8 is a diagram illustrating a typical plan or arrangement of pneumatic dispatch-tubes in accordance with myinvention. Fig. i is a sectional elevation of centralstation mechanism for introduclngthe carriers to the pneumatic tubes and of the aircompressing devices. Fig. 5 is an enlarged detail sectional View. Fig. 6 is an elevation, partly sectional, of a typical form of sub-station box when my invention is employed for transmitting or receiving letters or applied to post-oilice work; and Fig. 7 is an elevation of a preferable form of carrier.

Myinvention has relation to that class of pneumatic dispatch-tubes wherein each substation is connected to the central station by receiving and delivery tubes, and has for its object to dispense with the use of separate delivery and receiving tubes for each sub-station, and substitute therefor a single delivery-tube and a single receiving-tube common to all the sub-stations connected to or in circuit with said tubes, thereby effecting a material. reduction in the extent of pipe used and a saving in cost of plant or equipment. My invention has for its further object to control from the central station the movements of the carriers from the main tube to itsbranches and subdivisions of the latter, Wll0l'6- by the path of travel of the carriers is so directed that each carrier passes to its destination without interfering with the movement or blocking the path of other or following carriers.

a My invention has for its still further object to cause each carrier, as it passes from a main tube or a branch thereof and enters a sub-station delivery-tube, to automatically close the entrance of said substation tube by moving a switch located thercat, which, when so moved,

is held in a locked position by electro-rnagnetic devices designed to be operated to release said switch by the closing of an electric circuit by a moving carrier as it passes to the last sub station box on the main or branch deliverytube, whereby leading carriers passing through said delivery-tube successively close the substation tubes to the following carriers, but open a passage for the movement of the latter through said delivery-tubes.

Again, my invention has for its further ob ject to provide sub-station boxes for receiving and holding the carriers in a locked position 76 in said boxes, which are furnished with mechauism for automatically releasing and forcing the carriers out of said boxes, whereby the carriers are not ejected from the pneumatic tubes when they reach the sub-station boxes, 7 5 but are held therein until frcighted, and are automatically caused to return to the receiving-tubes leading to the central station, there- -by avoiding all handling ofthe'carriers by attendant at the substations. 7 8o My invention accordingly consists of the novel combination, construction, and arrangement of parts comprising a pneumatic-dis patch-tube system, having reference particularly to the following points: first, of a 0011- tral station having a dcl ivory and a receiving tube common to all the sub stations and switches therefor, as hereinafter described and claimed; second, of a central station having a delivery audareceiving tube common to all the sub-stations, manual and automatic switches therefor, electromagnetic appurtenances at the central station for controlling the movement of said manual switches, and electromagnetic devices located upon the tubes adjacent to said automatic switches for locking and unlocking them to permit of their return to their normal positions; and, third, of asubstation box or carrier receptacle provided with locking mechanism for retaining the carrier :09 therein, electromagnetic appurtenances for releasing said carrier, and devices for giving to the latter an initial return movement to cause it to pass out of the sul. -station box into delivery-tube B and open it through sub-staport, leading to the receiving-tube P for con- N0. 10, a like switch at the junction of two I sub-branches B B, the latter as well as the tubes A and B having branches B, which lead to the sub-station boxes L, and their junction is not, therefore,provided with switches C. By successively closing or opening, as abo e described, the various manual switches G of a system of pneumatic tubes, the carriers can be sent to all the sub-stations, and such result is obtained, however intricate may be the ramifications of the tubes. Where the system is divided into districts there will be a main tube, A, for each district, and the electro-magnetic appurtenances for the switches G of each district will be grouped or suitably arranged at the central station so that they may readily be operated without confusion.

At each junction of tube A or its branches B B, and a tube, B leading directly to a sub-' station, except as hereinafter noted, is placed a switch, M, automatically controlled in its movements by passing or traveling carriers, such switch being plainly shown in Fig. 2. The gravity of each switch M normally maint'ains it in the position indicated by the dotted lines was so as to close the passage-way through tion tube 13 to boxes L., Each switch M has an arm, m, which, when in its normal position, projects into the bore of the sub-station tube B so as to be in the path of the carrier, as indicated by dotted lines At the end of arm at is a lip, m, which is designed to engage with a catch, a, on an armature-lever, n, of magnets N,inclosed in coupling or box a at said junctions. As the carriers pass into the tubes B on their way to the substation boxes L they strike the arm m ofswitch M, de-

press the former and elevate the latter to seal tnbeB, and open the tube 13 for the passage of a following carrier to the next sub-station, and so on. As the carrier depresses the arm at, as above set forth, itslip'm engages with the catch a of armature a to lockarm m and hold the switch M in its elevated position, thereby keeping the tube B open for following carriers. Such position of the switch M is so maintained until its lock is released, as hereinafter set forth.

The sub-station boxes are constructed as follows:

Z represents the inlet-port, and Z the outlet ducting the carriers from the substations to the central office. The ports 1 Z merge into a common duct, L, located within the boxes L. The duct L in each box L leads to the top of the latter,'in which is an opening, P, for the insertion of packages, letters, &c., to carrier L when in position, as shown in substation box marked No. 1, Fig. 2.

Between the ports Z Z is pivoted a llap or valve, 0, which is moved over to the right of duct L or held in its normal position,as shown at station No. 1, Fig. 2, by the spring 0 Said valve is moved to the opposite side or to the left of duct L by the carriers as they pass out of tube B \Vhen valve 0 is in the former position, the way through duct L is open to tube 1, and when in the latter position the way through said duct leads from tube B. Said valve, therefore, guides the carriers into and out of the boxes L. The valve 0 has an opening, 0, near its lower end,which is sealed and unsealed by a valve, 0, pivoted to valve 0. The valve 0" is provided with an integral valve, 0, located on the side of valve o opposite that upon which the valve 0 is arranged, and it bears against the adjacent wall of the duct L, as shown. The gravity of the valve 0 is greater than that of the valve 0 so that when the former falls by gravity against the wall of duct L the valve 0 is moved away from valve 0 and unseals its opening 0, as in dicated at station No. 1, Fig. 2, to permit the air-pressure in tube B to pass or escape into tube P. The valve 0 is also provided with a pivoted valve, 0 The valves 0 and o which are located above the valve 0 and are kept up or in impingement with the adjacent wall of the duct L by the upper curved end of the spring 0 are on opposite sides of the valve 0, and they, together with valve 0 are moved or operated by their impingement against the walls of duct L as the valve 0 is moved to and fro therein, as hereinafter to be explained. The combined action of said valves guidesthe carriers in and out of the boxes L and cuts off and admits ai r-pressu re to the receivingtubes P as follows: Vhen the valve 0 is in its normal position, or to the rightof the boxes L, as shown at station No. 1, Fig. 2, the valve 0 falling by gravity against the adjacent wall of the duct L, closes the upper end of port Z and opens valve 0, while the upper curved end of spring 0 presses the valve 0" up against the ad j acentwall of the duct L to close the upper part of the port Z, so that blasts or pressure of air passing to port Z are diverted by valve 0 to opening 0 and port 1 to tubes 1?, thereby preventing such air passing to the boxes L and escaping through the top openings, i Such air-pressure is then used to return the carriers in tubes P to the central station; but when valve 0 is forced over to the left of boxes L, as shown at station No. 2, by the entrance of a carrier from port Zor tube B, the carrier in passing the valve 0 moves it to the left, or within a recess formed in valve 0. Such movement of the valve 0 depresses the valve 0 or the latter is then moved to seal opening 0 and cut off the airpressure to tubes 1?. Consequently the full force of the pressure is exerted upon said car rier to drive it to its proper positionin boxes L. As soon as the carrier reaches such position the valve 0 is returned to its normal po' sition by the reaction of spring 0 its upper curved end keeping the valve 0 up and the valve 0, dropping by gravity, opens the valve 0 to unseal opening 0 of valve 0 to admit air to tubes P, as above set forth. WVhen valve 0 so returns to its normal position its end 0, which is a yielding or I spring-supported end or pin, engages with or passes back of the tailpiece 12' of a pivoted platform, 10, and is thereby held firmly or locked in such position, so that it cannot be moved out thereof by the pressure of airinport Zor tube B. Said valve 0 being so locked it is always out of the way of and forms a guide for the carrier in the boxes as it is returned'through duct L to tubes P. WVhile the valve'ois locked by the tail-piece of platform 1), yet such engagement does not interfere with the free movement of platform to its horizontal' position when so impelled by its reacting-spring 19 Such movement of the platform is only made when the carrier is leaving the boxes L, so as to close the top of duct L. When the platform 1) is in its normal or horizontal position it rests upon the lip or end r of a pivoted lever, B. To the opposite end of the latter is secured an armature, r, for the electro-magnets R,suitably affi xed to the boxes L, as desired. Below the top of the latter are'placed two strong plate-springs, O O, having bent ends 0 O, which project into the line or path of the carrier. As the latter passes to its position within the boxes L it moves valve 0 aside, as above set forth, raises the platform 1) tea vertical position, and is forced against the ends 0 O of springs 0 until its lower edge passes above the end 1' of lever B. The carrier is thereby held or locked by lever B in such position until the latter is released, and when said lever supports said platform-orcarrier the armature r is then not attracted by the magnets R, butwhen attracted the end 'r of lever B is withdrawn from beneath the carrier, which is then free to pass to the receiving-tubes P, its initial movement being produced by the reaction of spring 0 0.

At the end of the branch B or at the junction between it and the last substation, tube B ,.there'is'no switch M, but in lieuthereof are contact-points s s, which are normally open. From contact 8 leads a wire, 5, to

1 ground 6, and from contact 8 leads a wire, 7,

to magnets R of box L, station No. 3, and from thence a wire, 8, to magnets N in box a, connected with tube B for station N o. 2. The remaining magnets R N of tube B- and its sub-stations are in circuit with each-other and with a battery, T, and an alarm or signal, t, Fig. 1, by means of wires 9, such circuit be ing plainly indicated in Figs. and 2.

The battery T is grounded, as illustrated, and it and the alarm are preferably located at the central office. tion of contacts 8 s makes an open circuit for said battery T, so that the armatures r and n are not attracted to their respective magnets R and N until the circuit of battery T is closed, such result being produced when a carrier passes the contacts 8 s. I

As the boxes L are made, a carrier, L is inserted in position therein, so that when connected to the tubes B and P of a pneumatic system a carrier is already in place in each box L. Said boxes are also provided with a pivoted lever, Z whose upper end is so arranged and is of such weight that it normally The normally-open posi-' I tends to move toward and bears against the to give thelatter an initial movement or start it to the left when its lock is released. The valve 0, in moving to its lockedposition, strikes and oscillates the lever Z projecting its end Z into the. port Z or in the path of the incoming carrier, and'the gravity movement-of the valve Z starting the valve 0 to the left withdraws said end Z* from port Z or out of the path of said carrier. When a carrier is in position within a box L, the tail-piece p of the raised platform 10 not only looks the valve 0 in its normal position, but also causes it to maintain the lever end Z in its projected position in port Z, and a carrier then coming into the latter is stopped or checked in its travel as soon as it impinges against the end Z* of lever Z as indicated by dotted lines, station No. 1, Fig. 2. As soon, however, as the carrier in the box L passes to tube P, the platform 1) drops, releases the lock on valve 0, and the gravity movement of lever Z then starts valve 0 to the left and withdraws carrier .free to be driven into box L by the air-pressure in tube'B Said'sub-station boxes with contained carriers and the pneumatic tubes with switches G and M being arranged as described, the switch or switches O are ma-' nipulated to direct the carriers fed into-the tube A at the central office to the tube 13, Fig. 2. The leading carrier traveling along the same meets the first switch M, and is diverted thereby to the tube B of the sub-station No. 1. As said carrier passes through tube B it depresses arm m of said switch to elevate thelat forth, to close the tube 13 and open tube B for the passage of following carriers. After look ing said switch said carrier travels through tube 13 until it meets and is detained by the end Z of lever Z as shown. Meanwhile said followin g carriers have raised and locked the remaining switches M, and passed to the inlet-ports of the remaining boxes connected to tube B, except for the last box, or box No. 3. The last carrier proceeding to the said end box, in pass ing the contactss 8, causes them to impinge and close the circuit of batteryT to magnets N and R, which then attract their armatures. The switches M are released and return to their normal position, and the ends 1" of levers R are withdrawn from beneath the carriers L in the boxes L, whereupon the springs O react to give'said carriers an initial return movement through duct L to the outlet-ports Z, and the platforms 1) are returned to their normal positions by their reacting springs p to unlock valves 0. The return-carriers, passing down the duct L, impinge upon and push down or aside the valves 0* and 0. The latter are thereby moved to close the openings 0 in valves 0 to cut off the air-pressure to tubes P. As soon as the lever ends Z are'withdrawn from the ports Z, the detained carriers therein are, by the pressure of air in tubes B driven through said ports, and strike against valves 0 and 0 to move valve 0 when it is in its locked position, and

end Z from port Z, thereby leaving the checkedter and lock it in such position, as above set them to the left of ducts L to provide a passageway through them for said carriers, which then pass through said ducts, lift the platforms 1), and enter into position in boxes L, whereupon they are locked therein by the levers B1, and the valves 0 are returned to their normal position by the springs 0, and the openings 0 thereof unsealed, as hereinbefore described, to admit air-pressure to tubes P to force the return-carriers therein to the central station. The tubes P follow the line of or are a duplication of tubes A B B, &c., and at their junctions they are provided with shunt-valves P P, united by a bar, P to cause them to move together and prevent blocking of the carriers at such points. The carrier first reaching the valves I moves them aside into the path of the joining-tube to stop or detain the carriers therein until said first-named carrier has passed said valves, as shown at z, Fig. 2. If desired, said junctions may also be pro vided with the movable guide pieces or bars P. hen the last carrier for tubes B passes the contacts 8 s and momentarily closes the circuit of battery T, the bell or alarm t is rung at the central station, notifying the attendant thereat that said circuit is in order, and that the boxes on said tube are supplied with carriers, whereupon feeding of carriers in a corresponding manner may be proceeded with.

for other parts of the system.

To feed the carriers into the main tubes A, I preferably employ the mechanism shown in Figs. 4. and 5, wherein NV represents a compressing-pump, IV a reservoir for the storage of compressed air or other motive power, and w a pipe-connection leading to tube A. Pipe 20 is provided with a chamber, a having a number of outlets, ca e, depending upon the extent of the system. The outlets a have pistons a with flanges for closing said openings, and hinged or flap valves a at their lower ends. The valves a are normally closed by the pressure of air in chamber a, to prevent the escape of airpressure from pipe '10. The pistons a are also provided with suit able operating-levers, a, which may be manually or otherwise operated, as desired.

\Vhen a carrier is to be introduced into tube A, the piston a of an outlet, a, is raised and the carrier placed therein resting upon the valves (0 as shown in Figs. 5 and 4. The piston is then forced down upon the carrier, which depresses or opens the valves a to permit the carrier to fall into chamber a and thence to tube A. The'fianges of the pistons prevent the escape of air-pressure from outlets a when the valves a are opened.

If desired, the boxes L may be configured and arranged, as illustrated in Fig. 6, and be provided with pipes or conduits V for the electrical or other wires, 2, 5, 7, or 9, used in connection with the system.

To cause the opening in the top of the carriers to align with the openings Z of the boxes L as the carriers reach their position therein,

they are provided with a helical cam, L, which impinges with a stud or guide, 11, secured to boxes L, as shown in Fig. 2.

To avoid friction between the'tubes and the carrier and to permit thelatter to pass through sharp or quick curves, it is made smaller in diameter than the bore of the tubes, and pro vided with a paper or other suitable bead 0r collar, L, of the size of the diameter of the tubes, as indicated in Fig. 7

\Vhile, as stated, I have shown my invention being especially adapted for postoffice work, I do not limit myself thereto, as it is obvious that it may be used for other desired purposes by changing the form of the carriers sired, each of the boxes L herein shown and officc by a separate receiving and a delivery tube. Again, the circuits for the batteries E and T may be opened or closed circuits, as desired. In either case the electromagnetic appurtenances both at the central and local stations will be arranged to produce the results above described.

The outlet of receiving-tube P at central station may be open or unprovided with valves; or, if desired, any suitable form of the latter may be applied thereto. The course of the tubes A, B, B, and B preferably parallel therewith; but it may be arranged in any de sired or .suitable manner.

Any terminal devices or valves may be secured to the ends of the tubes P at the central office; but as they form no part of my invention they need no further description.

What I claim is 1. In a pneumatic-dispatch tube system, a delivery and a receiving tube having branchof the carriers through said tubes, substantially as shown and described.

2. I11 a pneumatic-dispatch-tube systennthe combination of a central ol'fice, aseries of sub tube common to all of said sub-stations, and means for changing the course of the carriers through said tubes,substantially as shown and described.

8. In a pneu1i1atic-dispateh-tubesystem,the combination of a central office, substations connecting delivery tubes with branches, switches located at the junction of said tubes and branches, polarized magnets and armaturelevers for said switches, and an electric circuit leading from said magnets to electromagnetic appurtenances located at the central station, substantially as shown and described.

combination of central and sub stations, a connecting delivery-tube with branches, having at their junctions a switch with polarized magnet and armature lever, circuit-connections tubes P follows that of the various deliveryes and sub-branches com mon to all the stations or local termini connected to or in circuit therewith, and means for changing the course or local stations, a delivery and a receiving and of the substation boxes L. So, too, if dedescribed may be connected with the central IIO 4. Ina pneumatic-dispatch-tubesystem,the

from said magnet to a pole-changing switch 1 for releasing said lock, and mechanism for imlocated at the central office, substantially as shown and described.

5; The combinatiomwith the tubes A and B, of a switch, 0, polarized magnets D,armaturelever d, pole-changing switch F, and an electric circuit for the latter and said magnets, substantially as shown and described.

6. The combination, with tubesAand B, oi'a switch (1, polarized magnets D, armature-lever d, contact-points a a a a, polechanging switch F, electro-magnets G, with indicator or register, and an electric circuit for said electro magnetic devices, substantially as shown and described.

7. The combination, with tubes A and B, of a switch, 0, polarized magnets l). armaturelever d, contact-points a a a a", pole-changing switch F, elcctro-magnets G, lever H, locking mechanism I, register or indicator K, and an electric circuit for said electro-magnetic devices, substantially as shown and described.

8. The combinatiomwitli tubes A and B, of a switch, 0, polarized magnets D, armaturelever d, contact-points a a. a a", pole-changing switch F, electro-magnets G, lever H, locking mechanism I, register or indicator K, battery E, and circuit-conncctions, substantially as shown and described.

9. The combination of tubes A and B,

switch 0, electromagnetic operating devices therefor, and a register or indicator, substantially as shown and described.

10. The combination of tubes A and B, switchO, electromagnetic operating devices, and circuit-connections therefor, and a reg ister or indicator, substantially as shown and described.

11. In a pneumatic-tube system, the comination of delivery-tubes A B, &c., and the receiving-tubes P, having valves P P, substantially as shown and described.

12. In a pneumatictube system, the combination of a central ofiice, substations, and interposed recciviugtubes joining one to another between said central office and sub-stations, having shunts or valves at each junction there in, substantially as shown and described.

13. The combination,with sub-station boxes L, having delivery-tube B, of the branched or joining pipes P, having valves P at their junctions, as and for the purpose set forth.

14. In a pneumatic-dispatch-tubc system, a sub-station box having a delivery and a receiving tube terminating in a common duct or tube within said box, a valve located within said duct for guiding the carrier into and out of the box, a lock for holding the carrier in the latter, and means for effecting its release, substantially as shown and described.

15. A pneumatic dispatch-tube, sub-station box provided with inlet and outlet ports merging into a common duct within said box, valve mechanism for guiding the carrier into and out of said duct, a lock for the carrier, means parting to the carrier an initial return movement, substantially as shown and described.

16. A pneumatic dispatehtube, substation box provided with inlet and outlet ports merging into a common duct within said box, and valve mechanism for guiding the carrier into and out of the box, and for cutting off or admitting air-pressure from the inlet to the outlet port, substantially as shown and described.

1.7. In combination with a main or branch deliveiytube, B,of apneumatic-dispatch-tube system, a series of sub-station delivery tubes and boxes, switches located at the junction of the main and substation tubes, electromagnetic locking mechanism for said switches, and circuitconnection for said electromagnetic devices, which is made or broken by a moving carrier to release said switches, substantially as shown and described.

18. In combination with the tubes B and B, a series of switches, M, having arms on, projecting into the bore of the tubes 13*, electromagnetic appurtenances for locking and unlocking said switches, and circuit-connections for said appurtenances having contact-points s s, substantially as shown anddescribed.

19. The combination of tubes B B", switch M, with looking end m, lever-armature and electro-magnet N, an electric circuit therefor,

and contacts 8 s, substantially as shown and described.

20. The combination of tubes B B, switch M, with looking end m, armature-lever and electro-magnet N, contactss s, an electric circuit and alarm mechanism included therein, substantially as shown and described.

21. In combination with the tube A, chamber a having outlets a,valves a ",andflanged pistons, with operating mechanism, substantially as shown and described.

22. A carrier for pneumatic-dispatch-tube system, having a slotted end and the cam L". combined with a stationary lug to engage said cam to rotate and align properly the carrier.

23. A carrier for pneumatic dispatch-tubes of less diameter. than the bore of the latter, and having an anti-friction bead, L, and cam L", substantially as and for the purpose set forth.

24. A pneumatic-tube sub-station box, L, constructed substantially as shown and de scribed, and provided with a stud or guide, '0, in combination with a carrier provided with inclines, as and for the purpose set forth.

25. The sub-station box L, havinginlet-port and outlet-port, and a pivoted lever or catch,the endof which projects into the bore of theinletport, substantially as shown and described.

26. The sub-station box L, having inlet and outlet ports, a valve, 0, carrying valves 0 o, and 0, opening 0, and reacting-spring 0 substantially as shown and described.

27. The sub-station box L, having inlet and outlet ports, with valve mechanism, a movable platform, 1), a movable rest or locking mech anism therefor, and springs OO,substantially as shown and described.

28. The sub-station box L, having springs O O forgiving an initial return movement to the carriers in said box, substantially as shown and described.

29. I11 combination with box L, electromagnet It, armature lever It, having catch r, and an electric circuit for said magnet, substantially as shown and described.

30. The combination of boxes L, having eonnecting-tubes 13 and 1, the former being provided with switch M and electro-magnetic appurtenances,and the latter with valves P, substantially as shown and described.

31. In combination with pneumatic tubes A I and'their branches and sub-branches, of switches G and M, lever B, electro-magnet appurtances for said switches and lever, electric circuits therefor, and conduits or pipes V for the latter, substantially as shown and de scribed.

A pneumatic-dispatch-tube system having electric switches for changing the course of the carriers through the tubes, electrical conductors or wires between said switches and the central ot'fice, and a pipe or conduit, V, for said wires, substantially as shown and de scribed.

33. In combination with a pneumatic dispatch system, the chamber a having inlets a, gates or valves a, flanged pistons a, operating mechanism, compressing devices, and reservoir, substantially as shown and for the purpose set forth.

34. In a pneumaticdispatch-tube system, the combination of a central station, a series of sub-stations, a single delivery-tube common to all the sub-stations, and means, substantially as shown and described, for directing the course of the carriers to the sub-stations, mechanism for locking the carriers in the boxes of the sub-stations, and devices attached to said boxes for imparting to the carriers an initial return movement, as set forth.

In a pneu1natic-diSpatchtube system, a delivery-tube having a series of sub-station tubes connected therewith, switches located at the junction of said tubes, which are moved by a passing carrier, electro-magnetic locking devices and contact-points in circuit therewith, which are moved by a traveling carrier to cause said devices to operate to release said switches, substantially as shown and described.

36. In a pneumatic-dispateh-tube system, the delivery-pipe A, having branches and substation boxes, the switches O and M, the former being operated from the central station and the latter automatically moved by traveling carriers, substantially as shown and described.

37. In combination with tubes P, the shunts or valves 1 and guide P, substantially as shown and described.

38. A sub-station box for pneumatic tubes, having valve mechanism for guiding the carrier into and out of the box, and also for cutting off and admitting air-pressure to the outlet-tube of the box, substantially as shown and described.

39. I11 a pneumatic-dispatch-tube system, a single. delivery tube having branches, subbranches, and sub-station boxes, and switches located at the junction of the main and branch tubes and at the junction of the latter and sub-branches, and the latter being arrangedto change automatically the course of the carriers to the sub station boxes, substantially as shown and described.

40. In combination with sub-station box L, having opening Z", the movable platform 1), with retracting -spring 17*, substantially as shown and described.

In testimony whereof I affi x. my signature in prcsenceof two witnesses.

S. J. VAN Sravonnn, CHAS. VAN HORN. 

